Remove build warnings

Remove build warnings

 - fix implicit declaration of function
 - remove unused codes
 - remove unused parameter warnings

Change-Id: I830f9ada169e334a566bb696dee6cf9b46c87459
Signed-off-by: Jaewook Jung <jw0213.jung@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/20093
Reviewed-by: Phil Coval <philippe.coval@osg.samsung.com>
Reviewed-by: Uze Choi <uzchoi@samsung.com>
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Dan Mihai <Daniel.Mihai@microsoft.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>